Maintenance optimal medical therapy (OMT) was important for keeping patients alive after revascularization for complex coronary artery disease (CAD), according to extended follow-up of the SYNTAX cohort.
People who remained on guideline-recommended pharmacologic therapy 5 years after percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) enjoyed lower odds of all-cause mortality out to 10 years, reported Patrick Serruys, MD, PhD, of the National University of Ireland in Galway, and colleagues.
As the team reported in the , patients on OMT (i.e., at least one antiplatelet, statin, angiotensin-converting enzyme [ACE] inhibitor/angiotensin receptor blocker [ARB], and beta-blocker) had a 10-year mortality rate of 13.1%, which was significantly lower than the 19.9% of peers on two or fewer OMT components (adjusted HR 0.470, 95% CI 0.292-0.757) but similar to the 12.7% of people on three medications.
Based on this landmark analysis of 1,472 SYNTAX participants, patients should have at least three OMT drugs maintained at 5 years following coronary revascularization, Serruys' group concluded.
The nearly 7% absolute mortality difference in this report is "profound," commented William Boden, MD, of VA New England Health Care System and Boston University School of Medicine; and Bernard Gersh, MB, ChB, DPhil, of Mayo Clinic College of Medicine and Science in Rochester, Minnesota.
"These observations are extremely important in reaffirming the synergistic and beneficial effect of OMT on long-term mortality in patients undergoing revascularization with either CABG or PCI. As a corollary, it is worth noting that there are few data available to show benefit of OMT beyond 5 years," the duo wrote in an .
"We should also emphasize that OMT usage remains unacceptably low in both the U.S. and globally," they added. "Thus, OMT usage among patients undergoing revascularization should be considered an imperative to optimize clinical outcomes and reduce incident cardiovascular events during long-term follow-up."
The investigators had performed a post hoc subanalysis of , the extension study of the original cohort that was randomized to PCI or CABG for multivessel disease and/or left main disease. Participants included 1,800 people in North America and Europe, of whom 1,472 had sufficient drug information for the present analysis.
At 5 years, utilization of each OMT agent was reported to be 89.3% for antiplatelets, 83.9% for statins, 71.1% for ACE inhibitor/ARB therapy, and 74.0% for beta-blockers.
Yet just 46.1% of patients were on full OMT at 5 years. This group tended to be sicker and had more extensive CAD than the non-OMT group, suggesting that the 7% absolute difference in mortality may actually be an underestimation of OMT's benefit, Serruys' group suggested.
Of note, the survival benefit of OMT appeared to be driven by people who had undergone CABG, and antiplatelets and statins in particular were associated with lower mortality.
"It is recommended that patients undergoing CABG continue antiplatelet medication and statin beyond 5 years to avail themselves of the survival benefit of such therapy observed in this analysis," Serruys and colleagues specified.
However, these subgroup findings may be spurious or just reflect play of chance, the editorialists warned.
A major limitation of the study, they said, was the lack of information of OMT use beyond 5 years; the study authors had to assume that people who stayed on OMT at 5 years also adhered to OMT beyond that.
Boden and Gersh also pointed out that use of medical therapy was left to investigator discretion in the trial. "Thus, such post hoc findings and lack of rigorous OMT use may lead to confounding, as there are many factors that could influence OMT usage or not."
Finally, it is questionable that the current findings apply to contemporary practice: SYNTAX had been conducted in 2005-2007, before the advent of second-generation drug-eluting stents in PCI, advanced surgical techniques, and newer pharmacological therapies for secondary prevention, the investigators acknowledged.
"[T]he continuing controversy and polarization that has persisted for decades regarding which management approach -- an invasive strategy with revascularization versus a conservative strategy with OMT -- is preferred has long ignored the simple, practical consideration that these are, in reality, not competing treatment approaches, but rather complementary and potentially additive strategies to enhance optimal outcomes," Boden and Gersh wrote.
Disclosures
The SYNTAX Extended Survival study was supported by the German Foundation of Heart Research. SYNTAX had been funded by Boston Scientific.
Serruys reported financial relationships with Biosensors, Micell Technologies, Sino Medical Sciences Technology, Philips/Volcano, Xeltis, and HeartFlow.
Boden and Gersh had no disclosures.
Primary Source
Journal of the American College of Cardiology
Kawashima H, et al "Impact of optimal medical therapy on 10-year mortality after coronary revascularization" J Am Coll Cardiol 2021; DOI: 10.1016/j.jacc.2021.04.087.
Secondary Source
Journal of the American College of Cardiology
Boden WE, Gersh BJ "Defining the proper SYNTAX for long-term benefit of myocardial revascularization with optimal medical therapy" J Am Coll Cardiol 2021; DOI: 10.1016/j.jacc.2021.04.088.